Prosecutors are to be issued with revised guidelines on dealing with defendants with mental health issues.

The Crown Prosecution Service (CPS) said its guidance has been updated to reflect growing understanding of different conditions.

A random sample of nearly 400 cases across England and Wales found that one in five involved a defendant, victim or witness with a mental health issue.

Director of Public Prosecutions Max Hill QC (pictured) said: “It is no surprise that dealing with mental health issues is an everyday feature of life in the criminal justice system, so I’m determined that the CPS leads the way in ensuring that we treat this issue with the importance and sensitivity that it deserves.

“When mental health is a factor in a case, our lawyers must weigh up whether prosecution is the right approach, or whether there’s another way to protect society. Every case must be decided on its specific facts, and it’s essential that prosecutors have clear guidance as they make these complex decisions.

“It’s important that we get this right, and I look forward to hearing from both experts and the public on this new guidance.”

The revised guidance is designed to aid decision-making throughout the life of a criminal case, from the initial decision to prosecute, through fitness to plead, to sentencing.

It sets out information for prosecutors about different types of mental health conditions, the admissibility of confessions where a suspect has a mental health issue and potential legal defences for offences.

“There are a very wide range of mental health conditions and developmental disorders, and each will impact on individuals in different ways,” the document says.

“The fact that someone has a mental health disorder or condition may be relevant to the offence, but it may not.

“For this reason, the prosecutor should approach each case on its own facts and merits and assess the nature, extent and effect of the condition on an individual, together with the circumstances of the particular offences.”

The CPS has launched a consultation so members of the public, charities and health and legal professionals can submit their views on the guidelines before they are finalised.